[PD] direction

hello all pd-ers
not quite sure how to hrase this correctly. I need to be able to
dtermine direction of a string of bangs. more sinply, I need to know
if they are being triggered in the same direction from which they
started, or if they are bing triggered in the opposite. i need
positive or negative numbers respectively. stripping what i have to
the bone is this:
[ hslider ]
[route 1 2 3 4 5 6 7 8]
| | | | | | | |
o o o o o o o o
|
[other things] }
| }
[that give me] }
| } -----this stuff is all working well
[positive numbers] }
| }
[independent of direction] }
|
[number]
I need to be able to tell direction the slider is being "slid"
relative to the direction it started from.
hope i am being clear.
many thanks in advance
--
Ben C.